Amp Cabinet Building Time

[Travis Wilson]

So after a lot of reading and considering the frequency range of my 5-string, I'm taking the cabinet building plunge.

My initial thoughts:
15 x 15 x 11.5" open back external enclosure made with 1" poplar
10" Eminence Lil' Buddy speaker
3/4" Baltic Birch plywood for the baffle

I plan to drive it with an Egnater Tweaker 15.

Thoughts? Concerns? Suggestions?

More to follow,...

[Tom Wright]

You can be pretty much arbitrary in your choice of enclosure size and shape if it is open-back. I squeezed a Celestion 12" into a former practice amp box, roughly 13"x14"x8". Since the speaker is basically flush with the edges I used 1/4" ply for the baffle---the speaker provides plenty of rigidity and the box is very efficient and screaming loud with 100 watts pushing it. It gets plenty of low end with EQ, or I can lean it back for some acoustic coupling between the open back and the floor.

Or you could go closed-back and try the online design app at KBapps.com I used it for a small ported box with a 6.5" Eminence woofer. The small non-woofers are bright and tinny with no low end or power handling capacity--the Eminence (AlphaLite neodynium) is 100 watts and has good bottom as well top. If you research a speaker model you can find the Thiele-Small parameters like resonant frequency, useful for matching cabinets to speakers.

I would use a 12" since they are rather more efficient and always sound good to me. Consider the neodynium-magnet designs---I like the Celestion Century Vintage. I like open-back but do enjoy my little box if it is placed on the floor for better low end.

[Travis Wilson]

Wow! Thanks for the great information, Tom.

I'm kind of torn about the speaker size. Considering a 10" and 12" of similar design, the 10" will be less cost and weight. The things I cannot seem to find information about is clean headroom. Will the 12" have more headroom compared to the 10" all things being equal?

The one thing I do find concerning about 10" speakers is the resonance frequencies seem to be around 146Hz, which is D on the C-string. Do I need to worry about this?

[Tom Wright]

I find open-back cabinets sound better with low-resonance, more compliant speakers. The Little Buddy would not be my choice for a 10". I think the Delta Demon is interesting, plenty of power handling for the same price, low resonant frequency, etc. I would avoid a briight-toned speaker since you have enough of that from the instrument. The Demon looks a bit mellower than others.

Most of the neodynium speakers are pricey but the weight savings are becoming more popular. They tend to be brighter, although the Celestion I mentioned (Century Vintage 12") is sweeter-toned with a scooped midrange. But about twice the price of the Demon. In general a 12" will be substantially more efficient than a 10", giving you more headroom because you have more available power from the amp. For example, my 12" open box is punk-rock loud with a 25 watt amp, while the little 6.5" is just enough for jazz with 100 watts behind it.

[mandroid]

I got a Co Ax speaker I have yet to finish the cabinet for .. a horn tweeter
with its own Driver hides behind a Mesh Dome in the center of a 15" cone.
with a crossover of course..

probably should have a fridge dolly wheel set built into the cabinet..

Modified an Old Reel to Reel Tape machine cabinet ,
but its in my non workshop (5'6" clearance ) basement

for its travel covers, , but bogged down when its 'need' really didn't materialize

might have been handy, back in the day, with some of those blues jam amp wars.

now im in geezer land.

[Travis Wilson]

I find open-back cabinets sound better with low-resonance, more compliant speakers. The Little Buddy would not be my choice for a 10". I think the Delta Demon is interesting, plenty of power handling for the same price, low resonant frequency, etc.

Again, Tom, I really value your expertise and ear. Your suggestions have prompted more reading.

I think I will stick with a 10" speaker; I mostly just play for my own enjoyment. I really have no need for higher volume applications.

At the Eminence website, they list numerous parameters that influence cabinet design including Qts and EBP. They seem to rely upon these parameters to make recommendations as to speaker enclosure. It doesn't appear as though they offer the DD anymore, but when I looked at the Eminence spec sheet they recommended a sealed cabinet. When I take a look at the other 10" offerings (Ragin Cajun(75W), Copperhead(75W), Lil' Buddy(50W), they are all recommended for vented cabinets.

I have sent Eminence an e-mail with my proposed enclosure specs to ask their recommendation. It will be interesting to read their thoughts on resonance freq, speaker and cab combinations, and my intended use.

[Pete Martin]

I play through an Emminence Big Ben (15") and really like the fuller mid range sound.

[Travis Wilson]

For those who were interested, I thought I would update you on my progress.

I discussed the project with the folks at Eminence Speakers. They commented this is new territory for them. From a technical point of view, they said any of their current 10" speakers should be fine for my application. Their concluding comments were:

"I think Lil Buddy would be a great consideration. I'm still not sure whether or not a pro audio speaker, like a Beta-10A wouldn't be an even better choice because of the flatter, more neutral response. However, a guitar speaker, like Lil Buddy will sound more interesting and dynamic."

At any rate, I ditched the poplar because it was just too soft and difficult with which to work. I grabbed some pine boards, and I am building a box suited for either a 10" or a 12" speaker. I figure if I don't like the 10" speaker, I can always cut a different baffle with a hole suitable for a 12" speaker.

Here's a picture of my dovetailed pine box ready for glue:

[Bill Burch]

Travis,

Speaker cabinets are a fun project. Here's a pic of the one I build using lap joints, an 8" Jensen speaker I had, and a rattle can of Stew Mac cherry red lacquer. It's an extension speaker for the red Roland MicroCube battery powered amp. Portable and fun!

Bill

[Pete Martin]

Looking. Good Travis and Bill.